Carbohydrates are important energy sources which are indispensable to vital activities of mammals including a human. On the other hand, energy restriction or supply, such as restriction of the intake calories for diet and other purposes or effective energy intake in sports, is performed at various scenes in the modem society. Saccharides are typical examples of the carbohydrate, and various functional saccharides have been developed in order to respond to such requests.
Under such a background, patients suffering from diabetes and potential diabetes patients are known to be rapidly increasing in association with energy intake by carbohydrates in recent years. Insulin is poorly produced and secreted in diabetes patients, so that the increase in blood sugar concentration cannot be suppressed upon intake of a carbohydrate. It is known that a continued high blood sugar concentration state gives damages to fine blood vessels and neurons which induce a number of complications. Thus, these patients need to take such foods as not to cause a sharp increase in blood sugar level. Although restricting the intake amount of a carbohydrate is effective for suppression of the blood sugar level, it is not preferable to control the increase in blood sugar level by using a method of restricting the intake amount of a carbohydrate or getting energy from a food other than the carbohydrate. Therefore, the clinical practice guidelines by the Japan Diabetes Society provide a guidepost that diabetes patients shall get 50 to 60% of intake energy from carbohydrates.
Saccharides, which are slowly digested by a digestive enzyme without sharply increasing the blood sugar level, have hitherto been developed. For example, Patent Document 1 describes a process for preparing an isomalto-oligosaccharide which is a saccharide having a low glycemic index. Patent Document 2 describes, for example, an energy supplying drink comprising a branched dextrin having a structure wherein glucose or isomalto-oligosaccharide is linked to a non-reducing terminal of the dextrin through an α-1,6 glucosidic bond. Patent Document 3 describes a saccharide composition comprising a highly branched dextrin having a structure wherein glucose or isomalto-oligosaccharide is linked to a non-reducing terminal of the dextrin through an α-1,6 glucosidic bond, and isomaltulose, the composition gradually raising blood sugar level. Patent Document 4 describes, for example, a sustained type energy supplying agent comprising glucosidic bonds at a percentage of 9% or more in the molecule, and also describes that effects cannot be obtained when the percentage of α-1,3 glucosidic bonds is less than 9%.
However, a carbohydrate-derived energy supplying agent having both of slow digestibility and sustained digestibility functions and an energy supplying agent excellent in manufacture efficiency and cost have hitherto been unknown.